It has been estimated that functional amblyopia affects approximately 2% of the general population. The development of successful treatment procedures for functional amblyopia must be based on a thorough understanding of the mechanisms involved. Therefore, the present proposal is an application of psychophysics and physiological optics which utilizes an animal model of amblyopia and anomalous binocular vision. Rhesus monkeys with amblyopia caused by stimulus deprivation, strabismus, chronic cycloplegia and prims dissociation will be used as subjects in behavioral experiments on contrast sensitivity, increment-threshold sensitivity and binocular interactions using dichoptic stimuli. Visual evoked potential data will also be collected on the behaving, amblyopic monkeys. The data of amblyopic and nonamblyopic eyes will be compared and interperted on the basis of underlying physiological process which may be used to predict the animals' behavior. Treatment strategies will also be devised and tested on some of the amblyopic monkeys.